A Digital Artifact by VOLTAIRE E. MANALO M Arch - Urban Design | UP Diliman College of Architecture Archi 231 | 1st Semester AY 2020-21 | Profs. Lecciones and Silvestre 27 November 2020

1. FLOOD MITIGATION THROUGH
GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR
MARIKINA RIVERFRONT COMMUNITIES
A DIGITAL ARTIFACT BY VOLTAIRE E. MANALO
2018-21502 | M ARCH - URBAN DESIGN
ARCHI 231 | 1ST SEMESTER AY 2020-21 | PROFS. AARON JULIUS M. LECCIONES & JOSE DANILO A. SILVESTRE
UNIVERSITY OF THE PHILIPPINES DILIMAN - COLLEGE OF ARCHITECTURE
27 NOVEMBER 2020

2. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Source: Adapted from https://www.maptiler.com/
Situated on what is known as the Marikina Valley, the city of Marikina is
flanked by the Sierra Madre mountain range on the east and by the hills
of Quezon City on the west.
The Marikina River, with headwaters located in Rodriguez, Rizal, flows
through San Mateo and then to Marikina, before it reaches Pasig City
where it would meet the gates of the Manggahan Floodway.

3. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Source: Adapted from the Marikina City Zoning Map
12 out of the 16 barangays are the city’s
riverfront communities.
Sadly, even with the presence of the Manggahan
Floodway in Pasig City, the Marikina River still
overflows in times of intense rain.
To make up for this inadequacy, authorities have
been employing flood control projects for the
city.

4. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Multibillion-peso projects such as revetments, dikes and dredging works have been implemented. However, this proposal argues that such efforts have
solely relied on engineering solutions that seek to restrain the river in the hopes of blocking out floodwater. Aside from being monofunctional, they do
not consider alternative approaches to flood management.
The apparent ineffectiveness and high cost of these projects present an opportunity for the city to consider a more sustainable and complementary
approach — one that is characterized not only by resistance, but also by multifunctionality through mitigation and adaptation to flooding.

5. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
How can green infrastructure reduce the
flood exposure of Marikina riverfront
communities?
This proposal turns to green infrastructure to possibly complement the gray infrastructure or engineering methods that are available, and asked if it
could help reduce flood exposure. It is actually an approach that is normally discussed in landscape architecture, but may also also perform well in
understanding an urban design concern.
Urban design, after all, is collaborative and integrative in nature, especially in terms of the professions involved in its practice.

6. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Green Infrastructure is an interconnected
network of natural areas and open spaces…
(Benedict & McMahon, 2006)
Benedict, M.A., & McMahon, E.T. (2006). Green infrastructure: linking landscapes and communities. Washington, Island Press.

7. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
A green infrastructure proposal in Udon Thani, Thailand
Source: https://www.globalwaters.org/

8. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Cheonggyecheon Stream in Seoul, South Korea
Source: https://simple.wikipedia.org/

9. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Risk = Hazard + Exposure + Vulnerability
(UNISDR, 2015a)
UNISDR – United Nations International Strategy for Disaster Reduction (2015a). Global Assessment Report on Disaster Risk Reduction 2015.

10. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Fraser, S.A., Jongman, B., Balog-Way, S.A.B., Simpson, A.L., Saito, K., & Himmelfarb, A. (2016). The making of a riskier future: how our decisions are shaping future disaster risk – executive summary
(English). Washington, World Bank Group.

11. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Post-Ulysses Marikina City
Source: https://interaksyon.philstar.com/

12. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Post-Ulysses Marikina City
Source: https://philippinelifestyle.com/
What causes exposure? Population growth, migration, urbanization and
economic development, to name a few.
Risk also spreads as cities expand. When this happens, previously less
populated areas become more dense, as with the case of Barangay
Tumana, as shown here.

13. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Existing Urban Design Elements
Steep river access road from Riverbanks Avenue in Barangka Low-lying open spaces further contribute to flood exposure
Socialized settlement on a high-risk area in terms of flooding at Tumana Revetment walls at Riverbank Center in Barangka provide direct lanes for surface runoff

14. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Underlying Factors
Aside from the existing physical elements,
poor urban development practice is
probably the main underlying factor that
influences flood exposure in these riverfront
communities.
In the case of the gated community of
Provident Village as shown here, its
developers thought that landfilling would be
enough. However, such strategy just displaced
the water and did not improve flood risk
reduction for its residence.
In the context of major flood events in the
past, it could be said that our national
provisions for site development and city
planning are indeed insufficient, especially for
historical flood zones.

15. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Underlying Factors
Taking into account all of those existing conditions, it could be observed that comprehensive land use and zoning controls, combined with badly
planned and managed urban development, have indeed exposed these communities to high risks of flooding.
It also appears that with all those multi-billion engineering solutions, the riverfront communities remain highly exposed to floods over the years through
the course of major typhoons that have occurred.

16. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Past and Current Urban Design Management Strategies
Source: https://www.dpwh.gov.ph/
To address these problems, the DPWH cited
solutions, such as dams, retarding basins, dike
roads, levees, dikes, revetments with river
walls, installation of sheet piles, and dredging
works along the river.
The estimated implementation cost of these
projects was pegged at PHP 360 billion.

17. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Flood mitigation through green infrastructure: A conceptual framework

18. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Urban Design Goals
• Public spaces should support flood mitigation through the integration of green infrastructure.
• Access to the river should be more comfortable and safer to use.
• Site development should encourage improved pedestrian mobility.
• Areas of intervention should offer not just visual interest but also areas of refuge from hazardous events.
Flood mitigation through green infrastructure: A conceptual framework

19. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Urban Design Translations
Green infrastructure
For green infrastructure application, a system
of open spaces that support activities should
be created. Underutilized spaces may provide
opportunities for the integration of social and
outdoor recreational activities.

20. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Urban Design Translations
Green infrastructure
Wherever applicable, landscaping elements that protect against flooding should also be employed
in these riverfront communities. In identified areas with high-risk of flooding, interventions such as
urban forestry, pervious vegetated buffer strips, and reconstructed wetlands may be employed to
aid in flood protection.

21. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Urban Design Translations
Green infrastructure
Since building on floodplains is prone to
erosion, the use of ripraps is a typical flood
management solution in these riverfront
communities. However, these are
impermeable surfaces that prevent the
infiltration of rain into soils. Wherever
possible, protective infrastructure should be
designed and built as soft, landscaped
embankments — as fertile grounds for street
gardens and river parks.

22. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Urban Design Translations
Green infrastructure
In green infrastructure, surfaces should
promote water infiltration and retention. An
example of this would be the incorporation of
rain gardens, bioswales, and permeable
pavements.

23. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Urban Design Translations
Access
On concerns of improved access in terms of
comfort and safety, corridors to the river
should be designed with gentle grades, to slow
down surface runoff and to be more
accommodating to pedestrian traffic, including
cyclists, PWDs, and those on foot. Access
alleys to the river should also minimize
conflicts with external factors such as
vehicular traffic. Pedestrian canopies should
be provided as well to encourage walking even
when raining.

24. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Urban Design Translations
Pedestrian mobility
On improved pedestrian mobility, a safer and more convenient way to cross the river should be
provided, even in events of major river overflows. Safer, elevated bridges, with plantings that also
absorb and clean storm water can be provided for a more convenient connection between
communities.

25. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Urban Design Translations
Pedestrian mobility
A pedestrian and cycling riverside network should also be established in these communities. These
bike lanes and sidewalks may also be integrated with green spaces that cool the city, buffer noise,
and reduce air pollution.

26. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Urban Design Translations
Refuge
On providing areas of refuge, public spaces
should provide opportunities for informal
gatherings and chance encounters. These
open spaces could also be used as potential
evacuation areas, but its low elevation exposes
them to flooding, leaving them unusable and
unsafe. But by providing sufficient elevation
from the river, these nodes could also serve as
flood-free evacuation areas during other
hazardous events such as earthquakes and
fires.

27. FLOOD MITIGATION THROUGH GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR MARIKINA RIVERFRONT COMMUNITIES
Hinged on the concepts on green infrastructure and disaster exposure, it
could be assessed that using green infrastructure may lead to a reduction
of flood exposure, and may serve as a viable complement to the usual
engineering solutions to flood management in these riverfront
communities.
It wouldn’t be without its challenges, but by consolidating initiatives, long-
term management efforts, and technical know-how, the communities
involved would be able to identify and implement the solutions needed for
flood mitigation through green infrastructure.

28. FLOOD MITIGATION THROUGH
GREEN INFRASTRUCTURE
PROPOSED URBAN DESIGN INTERVENTIONS FOR
MARIKINA RIVERFRONT COMMUNITIES
A DIGITAL ARTIFACT BY VOLTAIRE E. MANALO
2018-21502 | M ARCH - URBAN DESIGN
ARCHI 231 | 1ST SEMESTER AY 2020-21 | PROFS. AARON JULIUS M. LECCIONES & JOSE DANILO A. SILVESTRE
UNIVERSITY OF THE PHILIPPINES DILIMAN - COLLEGE OF ARCHITECTURE
27 NOVEMBER 2020